As one of the Japanese I applaud your essays that introduce Japanese culture on the Internet. Possibly you'd rather want to hear comments from overseas readers. So I'll make my comment short. Actually I, born before the World War II, seldom read manga so that I have little to write about this topic. In my childhood, however, I enjoyed the manga Norakuro. (Note: Norakuro is the hero's name meaning "the black, stray dog.") It depicted the military life by the use of humanoid dogs. Those dogs were very humane, suggesting that the author Suiho Tagawa (1899—1989) did not like wars at the deep part of his mind in those days of militarism.Obachan replied:
Thank you for your comment! Yes, I know Norakuro. I have read only a few episodes so I don't know this manga very well, but I, too, had the impression that the author did not like the war. I also read somewhere that Osamu Tezuka respected Suiho Tagawa very much as his predecessor.Osamu Tezuka (1928—1989) is the famous author of comics about whom Obachan writes in the first piece of her essay. One of Tezuka's representative works is Tetsuwan Atomu (Atom with iron arms), the hero of which is the charming robot of the name Atomu. Tezuka contributed much to make manga one of unique cultures of Japan, as Obachan told us.
Another manga I liked to read in my boyhood was Fukujiro Yokoi's Putcher in Wonderland. It is SF manga, in which the boy Putcher and his robot friend Beri experience adventures of encountering Martians and the underground mankind, fight against those creatures, and finally establish peaceful relations with them. I had forgotten the story, but a website  reminded me of it.
That manga was published as a serial in the journal Shonen Kurabu (Boys' Club) after the World War II, from 1946 to 1948 . It was my junior high school days, and our young teacher of science said to us, "I don't recommend you to read manga, but Pitcher Putcher is an exception." On hearing the teacher's wrong citation of the title, some boys including me laughed secretly, and were proud of being regular readers of that manga.
I have to write also about the manga author Machiko Hasegawa (1920—1992), who learned the making of manga from Suiho Tagawa and was awarded the Prize for Honorable National in 1992 (the first winner of this prize was the home-run hitter Sadaharu Oh). Hasegawa's representative work is Sazae-san (Ms. Sazae). It is a comic strip dealing with the three-generation family Isono, in which Sazae is an active woman of the second generation. The strip first appeared in The Evening Fukunichi in 1946, moved to The Asahi-shimbun in 1949, and continued for 25 years in the latter newspaper.
One day when I was a graduate student, I saw the following strip of Sazae-san, in which no person of Isono family appeared: A thief of a scaring look stealthily comes into a house. In an empty room he takes out one of books from a bookshelf. Then he read it with a pleased smile. The last scene shows a corner of the street, where a sign with the words "Reading Week" stands.
The words "Reading Week" in Japanese consist of four Chinese characters. Hasegawa used the very difficult, original style character for the first one and a simplified style for the last. I disliked such loose use of Chinese characters. So, I sent a letter to her, writing like this:
I enjoyed your comic strip about Reading Week very much. However, I advise you consistently to use Chinese characters designated for daily use by the Cabinet. Many children read your strips, so that you have to be careful about their educational effects.I got no reply from Hasegawa. I believe however that she highly valued my advice, because I never saw her loose use of Chinese characters in Sazae-san after that. She must have been just before her forties at that time.